Abstract
Phosphate solubilizing rhizobacteria are considered as an important alternative to increase the availability of accumulated phosphates through solubilization. These increase the growth of plant by enhancing the efficiency of fixing biological nitrogen. This was studied through a pot experiment involving two Phosphate Solubilizing Rhizobacteria (PSRB) isolates,
Pseudomonas aeruginosa
and
Bacillus subtilis
along with Tri-calcium phosphate (TCP) on availibity of nutrients, biological composition of soil and yield attributes of rice crop at its growth stages. Experiment was laid in factorial completely randomized design (CRD) comprising of eight treatments replicated thrice with two factors viz. factor 1 with or without TCP (1 g
−1
soil) and factor 2 with single or combined inoculation of PSRB isolates. Considerable enhancement in available content of potassium (K), phosphorous (P), nitrogen (N) in soil was found with TCP 1 g
−1
soil (P
1
) and consortium of
Pseudomonas aeruginosa
and
Bacillus subtilis
broth culture at crop growth stages. Highest increase in available N (17.13% and 19.1%), available P (232% and 265%), available K (19.6% and 29.2%) over control were recorded in B
3
(consortium of
Pseudomonas aeruginosa
and
Bacillus subtilis
broth culture). Similarly, maximum nutrient uptake N (6.4%), P (15.8%) and K (8.9%) were recorded with same treatment. A considerable growth in soil microbial biomass carbon and dehydrogenase activity at crop growth stages was recorded on application of TCP 1 g
−1
soil (P
1
) and consortium of PSRB isolates'
Pseudomonas aeruginosa
and
Bacillus subtilis
(B
3
). Highest increase in microbial biomass carbon (16.4% and 16.5%) and dehydrogenase activity 34.7% and 43.8% over control were recorded in B
3
(consortium of PSRB isolates
Pseudomonas aeruginosa
and
Bacillus subtilis
) and was found best among all treatments in terms of yield (63.2%) and yield attributes; number of panicles
−1
plant (54.8%), number of grains
−1
panicle (156%) and average panicle length (63.9%).